Service
SERVICE
PAUL DEAN
A little car on the side?
Q Thanks very much for your crystal-clear response to Marcio Matandos' question regarding counter-steering ("Counter intuitive") in the May issue. I have been trying to reconcile my layman's understanding of this process to my 30 years of actual riding experience. Your answer enabled me to truly understand what is happening for the first time! But I have a follow-up question: My wife and I are considering moving to a sidecar rig. In general terms, what steering forces are at work when a sidecar turns? Does it function (and feel) like the car you describe in your response, since it is a two-track vehicle? Is counter-steering a factor at all with a sidecar attached?
Again, thanks for educating riders like me. I do not understand all of the engineering principles at work, but I always understand your explanations. Brian Ziemer Houston, Texas
AYour first assumption was correct: A sidecar rig is a twotrack vehicle, so it steers like a car, not like a motorcycle. You turn the handle bar left to go left, right to go right. counter-steering never comes into playunless, of course, you get radical and ride balanced on the motorcycle's original two wheels with the sidecar wheel dangling in the air. In which case
you would have to countersteer to maneuver the rig and prevent it from toppling over on its side.
A motorcycle with a sidecar in fact steers so much like an automobile that the bike's original front suspension often has trouble coping with the side loads imposed on the front wheel when turning. Telescopic forks were not designed for such loads and so tend to flex and chatter on tighter turns. This is why you sometimes see rigs on which the original telescopic fork has been replaced with another type, most often the Earles fork as used on older BMWs. These have a greater resistance to side loads and thus allow the rig to steer more efficiently.
The Manhattan project
QMy brother-in-law just bought a Moto Guzzi from a co-worker for pennIes on the dollar (at least we think so). It's a 2003 Moto Guzzi California Metal (1500cc?). It has just 1900 miles on the odometer and is in spanking beautiful condition. The previous owner says it is a limited-edition bike, 1 of only 7 made. We've been unsuccessful in determining its value, and even the Kelley Blue Book has nothing about the bike. I'm hoping you can shed some light on the subject or point us in the right direction. Josh Burch Manhattan, Kansas
I hate to disappoint you and your brother, but the Guzzi in question
is not all that special. From 2002 to 2004, Moto Guzzi named its California Stone cruiser models according to the material used on their finish. At one point, the lineup included the Titanium, the Aluminum, the Chrome and, yes, the Metal. Although Moto Guzzis never have been produced in large quantities, far more than 7 of the Metal versions were sold. And the engine displaces 1064cc, not 1500.
In 2003, the California Stone Metal had an MSRP of $8990. My check of the Kelley Blue Book online showed that the current retail value of the bike in Manhattan, Kansas, is $5645.Your brother's Guzzi is in mint condition with very low mileage, so it's no doubt worth more, but not by a huge amount. Moto Guzzis have quite a few loyal followers who are willing to pay a premium for a low-mile age sport model, but the cruisers are not held in the same high regard.
Milwaukee melody
I love your magazine, and when a debate arose between a friena and me, I thought you were the one who surely would know the answer. The question is, what gives Harley-Davidsons their distinctive sound? My friend says it is the way H-D sets the ignition timing, and I say it's in the design of the engine itself-a single-throw-crankpin V-Twin. Is either of us right or are we both wrong? Chris Graham Tamal, California
A Your friend is completely wrong; ignition timing has nothing to do with a Harley's exhaust sound. You, on the other hand, are almost entirely correct. The only terminology missing from your explanation is "narrow-angle." Ducatis, for example, are single crankpin wide-angle (90-degree) V Twins but have a clearly different exhaust sound than do Harley Big Twins and Sportsters, which are narrow-angle, 45-degree Vees. And while Honda and Suzuki both also make narrow-angle V-Twins, many of them have staggered dual crankpins, which produce yet another different exhaust note. In the `March, 2008, issue, I wrote a response ("The sound of music") to a question regarding the vastly different sounds made by various engines depending upon their configurationSingle, parallel-Twin, V-Twin, inline Four, etc.). If you have that back issue, you might want to read this par ticular reply, which deals with the intriguing and mysterious world of engine sounds.
The skinny about fat
Q I have a question about the super wide rear tires that are popular on s~ many bikes these days. The things you folks have said about wide tires in your articles have convinced me that they can make a bike harder to lean over into a corner, but what I don't know is why. The tires have a curved tread just like narrower tires, so why would width have an effect on the ability to lean? Anthony Spahn East St. Louis, Illinois
A It has to do with leverage. In the accompanying illustration, which depicts a super-wide rear tire and a more conventional, narrower one, there's a red line running through the middle of each tire. They represent the motorcycle's centerline, which also is the direction of the forces involved in cornering. (Actu ally, they're involved any time the bike is moving, but for our purposes here, we only need talk about cornering.) One of those forces, gravity, tries to make the bike fall inward in a turn, while the oth er force, centripetal, tries to make it stand up. During cornering, the com bined forces act through that centerline, and they must be kept in balance to pre vent the bike from either low-siding or high-siding.
Now look at the distance between each tire's contact patch and the point where its respective red line intersects the ground. You can see that the distance is considerably greater with the fat tire than it is with the narrower one. And that's where leverage enters the picture. Be cause cornering forces are acting through the bike's centerline, the farther the cen terline is from the contact patch, the more leverage those forces have to stand the bike up. In effect, that leverage throws the two forces out of normal balance, giv ing centripetal force an advantage over gravitational force. The end result is that a bike with a wide tire offers a greater initial resistance to turning than it would with a narrower tire, and then it has a > stronger urge to stand up once it's in the turn.
For completely neutral handling, the ideal tire would be one with a knife edge, kind of like a giant pizza cutter made of rubber. That way, there would never be any distance whatso ever between the contact patch and the centerline/ground intersection, and the bike would offer virtually no such resistance to turning. But the miniscule contact patch of a knifeedge tire would make riding a motor cycle so equipped too dangerous even to be considered; so bike engineers have to develop steering geometries and chassis designs, and work closely with tire companies, to help bikes with real-world tires handle as neu trally as possible. Ultra-wide rear tires raise the degree of difficulty for that task by a couple orders of magnitude.
Retaraded no more
Q I own a 2003 Suzuki SV1000S that I bought new, iarg~Ty on what I read in your magazine's reviews. I have not been disappointed, as it has proven to be an excellent real-world sportbike. That having been said, I am always looking for a little something more, and several websites recommend fitting a TRE (timing retard eliminator). Apparently, Suzuki retards the timing on its sportbikes in the lower four gears to soften the power. Fitting a TRE is supposed to really wake up the bottom-end performance of bikes like my SV. Is there any truth to such a claim? Will fitting a TRE negatively impact the life/reliability of my bike? Any advice you can give me would be very much appreciated as I have a limited budget and don't want to waste my money or do something that would negatively influence the lifespan of my cycle. Aaron Mouldey Posted on America Online
A Great timing, Aaron. Else where in this issue, there's a product evaluation on an Ivan's Performance Timing Retarder Elimina tor for a Kawasaki ZX-14. As you will read, we were extremely pleased with the added power and throttle response it provided in the Kawi's first four gears. It's cheap, easy to install and effected a performance improvement we could easily feel. And there is no reason to believe that it will have any negative effect on the 14's reliability.
Ivan's also sells a IRE for the SV1000 and numerous other motorcycles that have electronically limited performance in the lower gears; several other companies make similar products, as well. We've only tested Ivan's TRE, though, so I can't tell you how well any of the others workor if they even work at all. But based on our experience with the ZX-14, I feel confident in recommending Ivan's TRE for your Suzuki. And if you do install one, please inform us of the results.
Not exactly "fan mail"
Q So, Mr. Paul "Know It All" Dean, how much does Motion Pro pay you l~o pitch their tools? I haven't been keeping score, but it seems like there's a Motion Pro tool in almost every "Tool Time" that appears in Service. My guess is that either a check arrives in your mailbox every month or your garage at home looks like a Motion Pro show room. Or maybe both. Frank McConnell Sterling Heights, Michigan
A Yeah Frank, you're right: I have so many Motion Pro tools stacked in my home garage that I can barely get the door closed, and I've bought a small fleet of Ducati Desmosedicis with the under the-table cash I've gotten from that com pany. Yep, as long as I keep shamelessly > hawking Motion Pro products, life for me is glorious.
Homebrews
I spend a lot of time working on all kinds of bikes and cars, both old and new, so my hands often get extremely dirty and greasy. I generally use one of the commercial/industrial hand cleaners that contain pumice, which does an excellent job of scrubbing away the worst of the grime. But I've found that if I use an equal mixture of one of those cleaners and just about any of the better liquid house hold hand soaps, my hands come out noticeably cleaner, especially in the little cracks and fOtds in the skin. The hand cleaner's grit is invaluable in knocking out the tough stuff, and the hand soap's excellent cleaning qualities finish the job. I don't mix the hand cleaner and hand soap together in the same container; I just apply equivalent amounts of both in my palm before I begin washing.
Well, glorious except that you think I'm less than honest and sincere. Appar ently, either I've written something that really ticked you off or you're a Snap-on dealer who thinks my tool presentations have cut into your sales volume.
Fact is, Motion Pro products make frequent appearances in "Tool Time" for several reasons. First, they are motorcy cle-specific; readers don't need me to tell them that Craftsman and Snap-on make combination wrenches and sock ets. Motion Pro's owner and the vast ma jority of its employees are hard-core en thusiasts, most-but not all-of them off-road riders, and they use their experi ence to come up with ideas for practical, time-saving tools. They then try proto types in actual riding conditions to help develop those products into final form.
Second, Motion Pro has more bikededicated tools than anyone else and is constantly adding to its inventory. I al ways am on the lookout for tools from other sources, but the pickin's often are pretty slim outside of Motion Pro. Be sides, with shop labor costs steadily ris ing, more and more riders are looking to perform their own maintenance, and I feel an obligation to tell them about any cool motorcycle tools that might help them do those jobs more easily and efficiently.
And third, I've got my eye on a new Ferrari. Gotta keep those checks com ing, ya know.
Genesis of a standard
Q I got to wondering on the road recently, did the "normal" arrangement of motorcycle controls just evolve to its current configuration, or did some organization or engineers develop it for maximum performance? For example, twist vs. thumb-push throttle, gear patterns like "reversed" for racing, foot vs. left-hand clutch, etc. I can't help but wonder if the layout we all know is truly the optimum human machine interface for fast lap times. Dale Rhodes Littleton, Colorado
A Until the l970s, motorcycles were built with a practically unlimited assortment of control arrangements-leftfoot shift, right-foot shift; down for first and up for all other gears, up for first and down for all others; neutral between first and second, neutral below first; foot shift with hand clutch, hand shift with foot clutch; right-hand throttle, left-hand throttle; and on and on. This often made it difficult for riders to quickly and safely adapt when getting off one bike and onto another. Many motorcycle accidents were blamed on this lack of conformity, so the motorcycle industry and the governments in most major markets worked to come up with a throttle/brake/clutch/shift standard that has remained in effect for more than three decades.
When this standard was being devel oped, rider safety was at the top of the priority list and fast lap times were likely at the bottom-if they were even consid ered at all. Production racing at that time was not nearly as popular or evolved as it is today, and manufacturers did not design streetbikes to be quickly and easily converted for track use like they do now.
As far as thumb throttles are concerned, that standard was applied to snowmobiles and ATVs almost from the beginning. I'm not exactly sure when that throttle style was accepted, but I do know that one of the prime reasons was, again, safety The belief was that, unlike motorcycles, ATVs and snowmobiles require less overall skill for a novice to ride; after all, they don't fall over when you walk away from them. The thumb throttle was preferred over the twistgrip type because if the rider were to inadvertently apply too much throttle, the natural rearward thrust of his/her torso would tend to close the throttle; with a twistgrip, that same upper-body reaction would roll the throttle farther open.
Got a mechanical or technical problem with your beloved ride? Can't seem to find work able solutions in your area? Or are you eager to learn about a certain aspect of motorcycle design and technology? Maybe we can help. If you think we can, either: 1) Mail a written inquiry, along with your full name, address and phone number, to Cycle World Service, 1499 Monrovia Ave., Newport Beach, CA 92663; 2) fax it to Paul Dean at 949/6310651; 3) e-mail it to CW1 Dean@aol.com; or 4) log onto www.cycleworld.com, click on the "Contact Us" button, select "CW Service" and enter your question. Don't write a 10page essay, but if you're looking for help in solving a problem, do include enough infor mation to permit a reasonable diagnosis. And please understand that due to the enormous volume of inquiries we receive, we cannot guarantee a reply to every question.
